The photo-activated oxidase-like activity of gold nanoclusters: Implication for singlet oxygen generation

Gold-based nanomaterials have been widely used as photocatalysts, but little is known about their catalytic mechanism. In this work, we systematically investigated the oxidase-like activity of bovine serum albumin stabilized gold nanoclusters (BSA-Au25NCs) and gold nanoparticles (AuNPs) upon with different wavelengths. Our experiments showed that only BSA-Au25NCs could possess the photo-activated oxidase-like activity because the generation of reactive oxygen species (ROS) from BSA-Au25NCs was relatively efficient as compared to that of AuNPs. In addition, the interaction of BSA-Au25NCs with copper ions (Cu2+) further verified that singlet oxygen (O-1(2)) was the key reactive species in the dominant involvement of the photo-oxidase reaction. This work provides new insight into regulating the O-1(2) generation of BSA-Au25NCs, which might help in the design of AuNCs for other photocatalytic and photodynamic applications.